Abstract: A speech communication device includes microphones configured with: microphones M1 and M2 disposed at positions which are axisymmetric with a centerline in a width direction of a housing as a symmetric axis; and a microphone M3 disposed at a position which is on the centerline and closer to a speaker than the microphones M1 and M2 are. The speech communication device is further equipped with: a sound processor which includes: a beam former which is connected to the microphones M1 and M2 and forms a bidirectionality in which directionality is strong in two directions each perpendicular to the centerline and is weak in two directions each along the centerline; and an echo cancel unit which is connected to the beam former and the microphone M3 and removes a sound signal having been output from the microphone M3 from a sound signal having been output from the beam former.

Abstract: A speech communication device includes microphones configured with: microphones M1 and M2 disposed at positions which are axisymmetric with a centerline in a width direction of a housing as a symmetric axis; and a microphone M3 disposed at a position which is on the centerline and closer to a speaker than the microphones M1 and M2 are. The speech communication device is further equipped with: a sound processor which includes: a beam former which is connected to the microphones M1 and M2 and forms a bidirectionality in which directionality is strong in two directions each perpendicular to the centerline and is weak in two directions each along the centerline; and an echo cancel unit which is connected to the beam former and the microphone M3 and removes a sound signal having been output from the microphone M3 from a sound signal having been output from the beam former.

Abstract: Disclosed is an improved draft device for a bubble column used in a reaction wherein gas and liquid are mixed such as fermentation. The draft device consists of a plurality of vertical plates coaxially arranged within the bubble column such that each plate has one vertical edge in outwardly spaced overlapping relation to a vertical edge of an adjacent plate and has the other vertical edge in inwardly spaced overlapping relation to a vertical edge of the other adjacent plate.